Past Exposure to Hepatitis B A Risk Factor for Increase in Mortality?

Background:Chronic hepatitis B has been shown to increase mortality, but association of past exposure to hepatitis B and mortality has not been studied well. The aim of this study was to evaluate the risk of overall and liver-related mortality in individuals with past exposure to hepatitis B.Methods:The National Health and Nutrition Examination Survey III (NHANES III) and its related public linked mortality files were used for this study. The participants with presence of anti-HBcanti-HBs, in absence of hepatitis B surface antigen were considered to have previous exposure to hepatitis B. The overall mortality from past exposure to hepatitis B was assessed in participants without any chronic liver diseases (CLD) and in participants with chronic hepatitis C, alcoholic liver disease (ALD), and nonalcoholic fatty liver disease. The Cox proportional regression analysis was used to calculate adjusted hazard ratios.Results:A total of 15,650 individuals were included in the analyses. Past exposure to hepatitis B was an independent predictor of increase in overall mortality in individuals without CLD [adjusted hazard ratio (aHR)=1.29; 95% confidence interval (CI), 1.06-1.56; P=0.012] and those with ALD (aHR=2.25; 95% CI, 1.20-4.23; P=0.013). It was also an independent predictor of liver-related mortality in ALD cohort (aHR=7.75; 95% CI, 2.56-23.48; P<0.001). Past exposure to hepatitis B did not correlate with a significant increase in overall or liver-related mortality in chronic hepatitis C or nonalcoholic fatty liver disease cohorts.Conclusion:Past exposure to hepatitis B is associated with significant increase in overall mortality among individuals with ALD and those without CLD.